An all-bus-and-train option would take me 2 hours one-way and is a non-starter.
Driving to the Metro, then Metro-to-bus, would take an hour. Daily cost would be $13.75, after travel subsidy roughly $10. Plus some amount of gas to get to/from the Metro station (20 miles round-trip, call it .67 gallons or about $2.) So $12 and 20 miles of wear-and-tear on the car.
I'm spending about $7.50/day on gas for a commute that takes 30-60 minutes (avg. 45) and 60 miles of wear-and-tear on the car.
If I value the 15 minute difference at my hourly pay rate, and the 40 additional miles at a government reimbursement standard of around $0.50/mile, driving still wins.